完全生物降解高分子薄膜PHBV在土壤和水介质中的降解过程研究

Degradation of Completely Biodegradable Polymer Film PHBV in Soil and Water Media

采用土壤掩埋试验,研究了生物降解高分子PHBV(生物代谢合成的3-羟基丁酸酯和3-羟基戊酸酯的无规共聚物)薄膜在环境中的降解行为及其影响因素。研究表明,PHBV薄膜在土壤中的降解率要高于在水体中的降解率。PHBV薄膜在江西红壤中降解最快,60d时其失重率达80%,其次为吉林黑土、北京菜园土和垃圾土。PHBV薄膜在垃圾渗滤液中的失重率要大于农田水和自来水。影响PHBV薄膜在环境介质中降解的主要因素为微生物的数量和土壤特性。PHBV薄膜在水相中的降解行为包括微生物降解和水解反应,好氧菌和厌氧菌均能促进薄膜的降解。

Degradation of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) film in environmental media and the related influencing factors were studied. The results showed that the degradability of PHBV film in soils was larger than in sewage. Under experimental conditions, the weight loss ratio of PHBV films in Red soils from Jiangxi province was the largest, reaching 80%at 60 days of the degradation, while that in Black soils from Jilin province, Fluro-aquic soils and garbage soils from Beijing city degraded gradually. With prolongeddegradation time, the biomass of all soil samples increased, the organic matterof above samples was gradually comsumed. The pH values of Black soils, Fluro-aquic soils and garbage soils didn't vary remarkably, while that of red soils first increased continuously to maximum 7.57, then decreased to the initial value.The weight loss ratio of PHBV film in solid waste leachate was larger than thatin the waters from farmland and tap water. The biomass of micro-organisms in solid waste leachate and waters from farmland increased with the degradation time. The CODCr value of solid waste leachlate evidently decreased, the CODCr valueof waters from farmland first increased, up to peak at 20 days, and then decreased continually, while, that of tap water continuously increased because of the degradation and the biomass loss of PHBV. The dissolved oxygen of solid waste leachate and waters from farmland added with polymer film PHBV decreased continuously, while that of tap waters first increased, then decreased at 30 days of the degradation.